It will not stick for the new users. The best way to do this is either a GPO or prf files. Here is a link on how to setup a prf file to customize outlook profiles, http://technet.microsoft.com/en-us/library/cc179062.aspx.
Also some profile management tools have a way to generate outlook profiles. I know Appsense does and If I'm not mistaken ProfileUnity does this too.